Technical Field
The present disclosure relates to organic light-emitting display (OLED) devices, including an OLED device having an encapsulation structure capable of withstanding deformation and breakage.
Description of the Related Art
Display devices provide a variety of information graphically on a screen and are the core technology for information and communications dissemination. With increasing research, such display devices are becoming thinner, lighter and easier to carry, and capable of higher performance In light of such a trend, there is increasing interest in organic lightemitting display (OLED) devices, which control the amount of light emitted from an organic emission layer to display images.
An OLED device is a self-luminous device having a thin emission layer between electrodes, and thus can be made thinner In a typical OLED device, a pixel drive circuit and an organic light-emitting element are formed on a substrate, and light emitted from the organic light-emitting element passes through the substrate or a barrier layer, thereby displaying images.
The organic light-emitting element can easily deteriorate due to internal factors such as deterioration of the electrodes and the emission layer due to exposure to oxygen, deterioration due to the reaction between the emission layer and interface, and the like, as well as external factors, such as moisture, oxygen, ultraviolet rays and processing limitations of the device. Among these, performance and lifespan of the OLED device is significantly affected by oxygen and moisture, and thus packaging or encapsulation of the OLED device is an important issue.
The brightness and lifespan of a display device may be reduced, or undesirable appearance of dark spots and/or pixel shrinkage may take place, due to degradation by oxygen and/or moisture. To solve such problems, an encapsulation process for sealing an OLED device is used, in which an organic light-emitting element is deposited on a substrate and then a cover, such as a metal layer (cap or cover), a glass cap or cover, or one or more thin films or the like, seals the organic light-emitting element to block impurities from entering the OLED device. Examples of the encapsulation techniques include frit sealing, face sealing, thin film encapsulation, and the like.